物理化学学报 >> 2013, Vol. 29 >> Issue (08): 1655-1660.doi: 10.3866/PKU.WHXB201305222

理论与计算化学 上一篇    下一篇

径向电场对纳米管中水分子通量的影响

葛振朋, 石彦超, 李晓毅   

  1. 中国科学院大学材料科学与光电技术学院, 北京 100049
  • 收稿日期:2013-02-26 修回日期:2013-05-21 发布日期:2013-07-09
  • 通讯作者: 李晓毅 E-mail:lixy@ucas.ac.cn
  • 基金资助:

    国家自然科学基金(21274164, 21144001)和国家重点基础研究发展规划项目(973) (2012CB934001)资助

Effects of Orthogonal Electric Field on Water Flux through a Carbon Nanotube

GE Zhen-Peng, SHI Yan-Chao, LI Xiao-Yi   

  1. College of Materials Science and Opto-electronics Technology, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
  • Received:2013-02-26 Revised:2013-05-21 Published:2013-07-09
  • Contact: LI Xiao-Yi E-mail:lixy@ucas.ac.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21274164, 21144001) and National Key Basic Research Program of China (973) (2012CB934001).

摘要:

水分子在纳米通道中的运动对于生命活动、纳米器件的设计等都有着重要的意义. 现在已经证实, 在(6,6)的碳纳米管中, 水分子会以单分子水链的形式协同通过碳纳米管. 但是如何控制水分子的流量仍然是一个困难的课题. 本文研究了在径向电场作用下, 碳纳米管中水分子通量的变化趋势和碳纳米管的开关行为.发现在碳纳米管两端存在200 MPa的压力差时, 电场强度从1 V·nm-1增加到3 V·nm-1, 水分子通量线性减小. 当径向电场强度增加到3 V·nm-1时, 碳纳米管处于关闭状态, 水分子无法通过碳纳米管. 进一步, 我们发现水偶极与碳纳米管管轴夹角的平均值的概率分布和翻转频率都与水分子在纳米管中的个数有很大关系.

关键词: 碳纳米管, 径向电场, 分子动力学模拟, 水分子通量, 开关

Abstract:

Water transport in nanopores is important for many biological processes and the design of nanodevices. It has been demonstrated that water molecules are transported through a (6,6)-type carbon nanotube (CNT) by forming single-file chains. However, a controllable water flow through a CNT remains difficult to achieve. In this paper, we investigated how to control the net flux of water molecules transported through a CNT and the on-off gating behavior of the CNT using an orthogonal electric field. With a 200 MPa pressure difference acting on the top of the first layer of water molecules as the driving force, the net flux of water molecules decreased linearly as the orthogonal electric field strength (E) increased from 1 to 3 V· nm-1. When E increased over 3 V·nm-1, the flow of water molecules through the CNT was turned off and the net flux was almost zero. Both the orientation of water dipoles and flipping frequency were strongly correlated with the water occupancy in this case.

Key words: Carbon nanotube, Orthogonal electric field, Molecular dynamics simulation, Flux of water molecules, Gating

MSC2000: 

  • O643